davis



(No Model.)

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J. O. DAVIS.

PUMP.

Patented Oct. 8, 1889.

l I .lllllilllllli? i UhTIT'ED STATES PATENT OFFICE.

' JOHN 0. DAVIS, or HARTFORD, CONNECTICUT.

PUMP.

srscrmcA'rron forming part of Letters Patent no; 412,480, dated October 8,1889. Application filed January 6, 1887. Serial No. 223,565. (No model.)

To all whom it may concern.-

Be it known that I, JOHN OJDAVIS, of Hartford, in the county of Hartford and State of Connecticut,have invented a certain new and useful Improvement Pertaining to Pumps, of which the following is a description, reference 'being had to the accompanying drawings,

tion on the plane Y Y, with the pump de-- noted in outline simply, as such view would show but one of the pumps. This section cuts through one of the check-valves. A similar sectional view of the other check-valve is just the same.

This improvement pertains to a pump apparatus in which there are two pumps, each a lifting and forcing pump, used generally for forcing water into steam-boilers under pressure in a substantially continuous stream, and the object of the improvement is to permit the two pumps to run regularly and continuously at a regular and uniform speed, and yet adjust and control the amount of water they shall feed or force into a steam-boiler or the like, without varying the strain upon the pumps or causing them to pound when the outlet is closed or reduced; and my improvement consists in a double cylinder lifting and forcing pump in combination with a by-pass valve of peculiar construction, as more particularly hereinafter described, and pointed out in the claim.

The letter a. denotes one of the pumps proper as a whole, of which there are two alike, as indicated in outline in Fig. 3.

The letter b denotes a suction-duct leading to the barrel of the pump a, of which suctionducts there are two just alike. Each suctionduct is furnished with a check-valve 0, two of which are just alike.

So far I have described what is old. I will now describe the new feature. The lower part of the frame-work is chambered out and forms a common reservoir for the supply ofwater to both pumps, the inlet-pipe leading into this chamber and both the suction-ducts, in which the check-valves are located, leading out of it. The two suction-ducts b are connected by the communicating-duct d,

which is furnished with an adjustable stop valve 6, the stem of which is threaded for a short distance and. fits a threaded socket in the frame-work, and then passes through an ordinary stufling-box and terminates in a handle, whereby this connecting-duct may be wholly closed or opened to any desired degree. In the ordinary form of pumping device the pistons in the pump-cylinder reciprocate alternately with a regular and uniform motion, which causes the check-valves to rise and fall alternately with a regular and uniform motion that feeds a certain amount of water each time they reciprocate, which, if the outflow is cut off or checked in any manner, causes a severe strain upon the pumps by back-pressure, and this oftentimes seriously injures the pumps if they are not stopped. L,

Phe operation of my improved device is as follows: When the piston rises, the liquid is drawn into the chamber 1) from the supply,

the suction lifting the valve 0 and allowing the water to flow around it. When the piston descends, the valve 0 is closed and the liquid is forcedvinto the boiler'or other receiver. It

is desirable to keep the pump in operation at a uniform speed, but not always necessary to supply the same quantity of water to a boiler, and to overcome any baclvpressure produced by not carrying away the full supply from the pump a duct d is provided which communicates with the suction-duct of the other pump, and the surplus water escapes through this way d in any quantity desired. This is regulated of course by the'position of the valve e. Thus by regulating the size of the opening around the valve 6 the amount of feed-water can be regulated and the pressure on the pumps maintained constant, regardless of the amount of liquid required by the boiler or other receiver, and the surplus water used to supply the other pump. In case no water is needed, the pumps can still keep in motion, but merely force the water from one barrel to the other through the connecting-duct.

forcing pumps, a frame-Work chambered out to form a common reservoir to supply both pumps, and having a suction-duct leading from the chamber to each pump, a valve seated in each suction-duct with an upwardprojecting stem fitting a socket in the framework to insure its seating itself properly, a channel leading from one suction-duct to the other, a valve seated in an enlargement of said channel, said valve having a portion of its stem threaded to fit a threaded socket in the frame-work, with its end projecting beyond the frame-Work and terminating in a handle, whereby the capacity of the connecting-channel may be regulated by turning the handle of the valve-stem, substantially as described, and for the purpose specified.

JOHN DAVIS.

Witnesses:

H. R. WILLIAMS, A. B. JENKINS. 

